1. Field of the Invention
The present invention relates to an electromagnetic coil for use in an electromagnetic actuator and others.
2. Description of the Related Art
In a known electromagnetic coil of this type, cooling plates made of metal are disposed at axial positions along the axial direction of a conductor winding formed by winding an electrically conductive wire a plurality of times, for example, as described in Japanese Patent Application Laid-Open (kokai) No. 2013-12645. In the electromagnetic coil described in Patent Document 1, the front and back sides of the cooling plates are covered with respective high-thermal-conduction insulating members in the form of ceramic layers.
In the electromagnetic coil described in Japanese Patent Application Laid-Open (kokai) No. 2013-12645, at an axial end surface of the conductor winding, recesses are formed at the surface of turns of the electrically conductive wire wound a plurality of times, or some turns of the electrically conductive wire protrude. Thus, when the cooling plates are brought in contact with the respective axial end surfaces of the conductor winding, contact between the end surfaces and the cooling plates (more specifically, the high-thermal-conduction insulating members) becomes insufficient, resulting in a deterioration in heat radiation from the conductor winding.